What wattage limits are in place according to the National Electric Code for in-concrete slab heating?
NEC 424.98 (A) Installation in Concrete or Poured masonry: Shall not exceed 33 watts/ft2, with NO FLOOR COVERING. Our slab rolls provide 20 watts/ft2.
NEC 424.99 (B) Installation under floor covering: Shall not exceed 15 watts/ft2.
Maximum cable wattage PER LINEAR FOOT: NEC 424.44 (A) Constant wattage cables cannot exceed 16.5 watts per LINEAR FOOT.